1. Field of the Invention
This invention relates to lasers, and more particularly it relates to flowing gas lasers excited by means of an electric discharge transverse to the gas flow direction.
2. Description of the Prior Art Including Prior Art Statement
Exemplary high power, cw, electrically excited flowing gas lasers are disclosed in U.S. Pat. No. 3,962,656 to E. R. Peressini and in U.S. Pat. No. 3,970,962 to E. R. Peressini et al, both patents being assigned to the assignee of the present invention. In lasers of this type, the laser gas flows through an excitation region where it is excited to a condition of population inversion by an electric discharge controlled by an electron beam introduced into the excitation region from an adjacent electron gun. The discharge is established between a pair of electrodes disposed on opposite sides of the gas flow channel at the excitation region. The electrons in the electron beam and in the discharge current travel in a direction transverse to the gas flow direction.
During operation of discharge-excited lasers of the aforementioned type, electrical streamers formed in the discharge sometimes are carried by the flowing laser gas slightly downstream from the region between the discharge electrodes. Thus, the discharge is caused to spread out, and some of the input power is deposited into the flowing laser gas downstream from the region where the laser beam is generated.